1. Field of the Invention
The present invention relates to metal roof systems and shingle roof systems that are used in both commercial and residential buildings and, more particularly, to vent coverings which allow for airflow and prevent foreign contaminants such as insects, birds, small animals and excess water from entering a roofing system by forming a partial seal.
2. Description of the Prior Art
The life span of any roof will be increased if adequate ventilation is provided along the top vent of the roof. Ventilation is needed to allow air to flow through and out of the roof interior and out of the vent which is located along the top of the roof where the two slopes of the roof nearly meet. Having adequate airflow that uses roof ventilation is a proven construction technique that is used in both new construction and remodeling existing structures. Ventilation of the roof has been historically accomplished through the use of fabricated metal enclosures and complex fabricated plastic parts. In the 1970's, flexible reticulated polyurethane was used to achieve acceptable airflow and to solve the invasion of foreign debris small animals. While this material solved numerous problems, it still had several troubling shortcomings such as shrinkage, early deterioration, insufficient strength, low ultraviolet resistance, low tear resistance, density and low fire retardancy.
Beginning several years ago and in response to customer requests, research was directed to providing a better venting product than those then in use. Experimentation continued into the year 2000 and thereafter. Different materials were tested, but no acceptable version was identified until a few years ago when it was determined that reticulated polyurethane had the essential characteristics needed for a successful venting system. Later it was determined that this material when used would quickly begin to degrade because of poor ultraviolet resistance, poor hydrolytic stability, and the inability to meet building codes as a fire-retardant material used in construction.
More recently, a new, flexible, reticulated, polyurethane material was produced and, when tested, verified that it would prevent excess water from being driven by wind back through the ventilation material and into the roof interior. It was designed to withstand ultraviolet radiation for prolonged periods, and it was also designed to comply with building material standards and made fire resistant. The material proved successful and demonstrated that it would provide superior airflow for a roof and prevent wind-driven rain from entering the building. Thus an improved vented closure strip has been and continues to be very desirable, and it is to that end that the present invention is directed.